Effects of cholera toxin and guanosine 5′-[βγ-imido]triphosphate on β-adrenergic-receptor affinity
| Autor: | G W G Sharp, J Fischer |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Agonist
Cholera Toxin History medicine.medical_specialty Erythrocytes Adrenergic receptor medicine.drug_class Guanosine Propranolol medicine.disease_cause Education chemistry.chemical_compound Internal medicine Receptors Adrenergic beta medicine Animals Alprenolol Receptor Guanylyl Imidodiphosphate Erythrocyte Membrane Cholera toxin Isoproterenol Receptors Adrenergic Computer Science Applications Endocrinology Biochemistry chemistry Dihydroalprenolol Triphosphatase Guanosine Triphosphate Anura Research Article medicine.drug |
| Zdroj: | Biochemical Journal. 176:505-510 |
| ISSN: | 0306-3283 |
| DOI: | 10.1042/bj1760505 |
| Popis: | A comparison was made of the effects of cholera toxin and p[NH]ppG on the binding affinity of beta-adrenergic receptors in toad erythrocyte membranes. This was determined by studying the ability of isoproterenol and propranolol to compete for the receptor with (-)-[3H]dihydroalprenolol. p[NH]ppG decreased the receptor affinity for the agonist isoproterenol (i.e. a ‘right’ shift in the displacement-concentration curve), but was without effect on the affinity for the antagonist propranolol. Toad erythrocyte membranes after treatment with cholera toxin exhibited increased receptor affinity for isoproterenol (i.e. a ‘left’ shift in the displacement curve), but did not affect the affinity for propranolol. p[NH[ppG was able to exert its right shift even in cholera-toxin treated membranes. The ability of cholera toxin to alter beta-adrenergic-receptor affinity is interpreted as further evidence that the toxin affects the nucleotide-regulatory component of adenylate cyclase. The regulatory component affected may be the catecholamine-sensitive guanosine triphosphatase. |
| Databáze: | OpenAIRE |
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